Apparatus for portioning dough

ABSTRACT

An apparatus for portioning dough has a filler hopper (31) for the dough in which hopper a pre-portioning tool (51) in form of two star rollers (32) is disposed which rotate in inverse direction and are driven by a drive device if the amount of dough in a chamber (30) below decreases a predetermined value. From this chamber the dough (30) is pressed by a pusher device (25) in receiving openings (4) on the periphery of a step-wisely rotated drum (2). The volume of dough in the chamber (30) is controlled by a capacitive sensor (35) embedded into the wall (36) of the filler hopper (31) so that this sensor (35) does not interfere with the stream of the dough.

The invention relates to an apparatus for portioning dough, comprising afiller hopper for the dough leading into a chamber from which the doughis moved by a pusher member to at least one receiving opening on thecircumference of a drum bearingly supported for rotation around ahorizontal axis, which receiving opening passes the chamber and, incooperation with a stripper edge makes the proper portioning, apre-portioning tool being provided in the filler hopper separate fromthe pusher member, preferably in form of two star rollers movedsynchronously with opposite direction of rotation, and wherein a sensormeans for the filling amount of dough in the chamber or, respectively,in the filler hopper is provided below the pre-portioning tool forcontrolling the drive means of the pre-portioning tool, and wherein anadjustment member for the volume of dough received by the respectivereceiving opening is provided.

An apparatus of this kind is known (for example GermanOffenlegungsschrift 2,244,469 and 2,853,270). Within the knownconstruction the sensor means is formed by a rod adjustably supportedwith respect to its height position within the filler hopper above thepath of the pusher member, which rod switches on the drive means of thestar rollers when the amount of dough in the chamber decreases apredetermined value, so that dough is fed to this chamber. The doughpushed away by the pusher member lifts the rod whereby the drive meansof the star rollers is switched off again and the stillstanding starrollers with their arms facing each other shut off the travel of doughto the chamber. Within this known embodiment it may happen that agreater amount of dough jams the rod so that it cannot more swivel toabove, particularly if dough is jammed between the wall of the fillerhopper and the rod.

Further it has been shown that difficulties arise if by means of thesame apparatus alternatively dough portions having a low weight areproduced with portions having a greater weight. It is known to providethe apparatus with an adjustment device by means of which the volume ofthe receiving opening at the proper portioning position can be adjustedto the desired volume of the dough portion. Since it has been shown thata smaller volume of dough shall be present in the chamber guiding thepusher means when producing dough portions of low weight, it is knownwithin apparatus of the initially described kind to consider thiscircumstance by corresponding adjustment of the switch actuated by thesensor means. However, the greater volume of dough in the chamber or,respectively, within the section of the filler hopper below the starrollers is, the greater is the danger that the sensor rod is jammed bythe dough. In dependence from the jammed position of the sensor meansthis may have as a consequence that either too less dough is conveyed inthe chamber by the star rollers, what means the danger of idle portions,or that too much dough is conveyed into the chamber so that there thedough is excessively squeezed during movement of the pusher member.

The invention has at its object to avoid these disadvantages and toimprove an apparatus of the initially described kind so that jamming ofthe sensor means by the dough is reliably avoided even if great amountsof dough are do be controlled in the chamber, or if the volume of thedough portions to be produced must be changed. The invention solves thistask by the fact that as the sensor means at least two stationarycapacitive sensors responsive to the approach of wet mass are provided,which sensors are inserted one above the other into the inner surface ofthe wall of the hopper member or, respectively, of the chamber and arerelated to different volumes of the dough portion to be produced, andthat for adaptation to different volumes of the dough portions to beproduced the respective active sensor ist selectable by means of achange-over switch which is coupled to the adjustment member for thedesired volume of dough. Such sensors are known in other technicalfields as capacitive approach indicators or, respectively, capacitiveapproach switches. They are based on a change of the capacitiveproportions when the mass to be controlled approaches, sensors workingalong the capacitive principle being suitable for non-ferromagneticmasses. Whereas within the initially mentioned known apparatus themovement of the sensor relative to the walls of the chamber is used forthe detection how much dough is present within the chamber, such arelative movement is totally avoided at the inventive sensor. Therefore,the movement of the sensor cannot more be jammed and any wrongindication caused by such a jamming is avoided. A further advantage ofthe use of an electric-capacitive sensor is that such a sensor respondsonly then if a substantial mass of dough approaches close by, but doesnot already respond to small amounts of dough. Thereby, falseindications caused by small amounts of dough are avoided, for example bydough rests that adhere to the star rollers or to the walls of thefiller hopper and then fall down. Whereas within the initially describedknown embodiment the sensor must be disposed in the free cross sectionof the filler hopper if the sensor should be efficient, within theinventive embodiment the sensor is in no way an obstacle to the path ofdough.

Further, the invention solves the problem of changing the apparatus todifferent volumes of the dough portions or dough weights, respectively,so that detrimental influences upon the sensor activity are avoided.When changing from one volume of the dough portion to another, only thesensor related to the new volume must be switched on and the sensorrelated to the prior volume must be switched off in order to adjust tothe new circumstances. Coupling the change-over switch for thecapacitive sensors to the adjustment member facilitates this change andavoids erroneous handling. There are no difficulties to dispose aplurality of sensors within the filler hopper due to the fact that thesesensors are installed in the wall of the filler hopper or of thechamber, respectively.

According to a preferred embodiment of the invention each sensor isdisposed flush with the inner surface of the wall of the filler hopperor of the chamber, respectively. This results in the lowest possiblefriction resistances for the dough sliding in the filler hopper or,respectively, in the chamber.

From the U.S. Pat. specification No. 3,939,360 it is known to applycapacitive approach sensors in form of strips to the outer wall of aninfusion bottle in order to control the filling level of the infusionsolution within the bottle. Such an arrangement would not be suitablewithin an inventive dough portioning apparatus.

It is of particular advantage to couple the change-over switch and theadjustment member also to an adjustment member for varying the kneadingspace of a kneading device disposed in the region of the upper summit ofthe drum. In this manner one adjusts automatically to the fact that abigger dough portion needs more room for the kneading operation.

In most cases apparatus of the initially described kind are soconstructed that the receiving openings are disposed in a plurality ofrows on the circumference of the drum, each row containing a pluralityof receiving openings. Within such an embodiment it is suitable withinthe spirit of the invention if each sensor extends in form of a ledgeover substantially the entire length of that wall of the chamber whichextends parallel to the axis of the drum and adjacent thereto. Thesensor, therefore, is common for all receiving openings of the row andis disposed at that wall at which the dough is mainly pressed to aboveby the pusher member at its forward movement.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings an exemplative embodiment of the invention isschematically shown. FIG. 1 shows a vertical section through theapparatus, FIG. 2 is a view from above to the apparatus, partially insection.

In a frame 1 a drum 2 is supported for rotation around a horizontal axis3. A plurality of receiving openings 4 for the dough to be portioned isdisposed on the circumference of the drum 2 in four rows runningparallel to the axis and distributed in equal distances over thecircumference of the drum 2. A portioning station 5, a kneading station6, an ejecting station 7 an a further station 8 are distributed over thecircumference of the drum 2, the later station may constitute anunoccupied station, which, however, may also be used for specialpurposes, for example for flowering or oiling of the receiving openings4. The drum 2 is stepwisely driven such that the receiving openings 4advance for one station at each step. In each receiving opening 4 apiston 9 is shiftably guided in radial direction, which piston is guidedalong curved path 10 of a cam disc 11 in the interior of the drum 2.Suitably two such cam discs 11 are provided (FIG. 2) which are keyed toa central shaft 13 of the drum 2 at the two front ends of the drum 2.The pistons 9 are guided by means of rods 12 (FIG. 1) in the relatedcurved paths 10 of the two cam discs 11. By a not shown drive means theshaft 13 is so oscillatingly driven in direction of the double arrow 48that the curved discs 11 are also rotated together with the drum duringthe forward movement of the drum 2 for one step, no relative movement ofthe cam discs 11 relative to the drum 2 occuring during this forwardmovement of the drum 2 and therefore also no shift of the pistons 9 inthe receiving openings 4. During the stillstand of the drum 2 betweentwo subsequent steps of feed, however, the cam discs 11 are fed backinto the starting position, whereby the pistons 9 are advanced orretracted in correspondence to the shape of the curved paths 10. Theshape of the curved paths 10 is such that at the portioning location 5the piston 9 is retracted in the receiving opening during the stillstandof the drum, what causes a suction effect on the dough to be broughtinto the receiving opening 4. At the kneading station 6 the pistons,starting from the end position reached in the portioning station 5, aregradually further retracted in the receiving openings 4, so that duringthe kneading process room is made for the transition of the dough piecein a substantially spherical shape. To the contrary, at the ejectingstation 7 each piston 9 is advanced during the stillstand of the drum 2until the front surface 14 of the piston 9 is flush with the outercircumference surface 15 of the drum 2. In the unoccupied station 8 thepistons 9 may remain in this position, however, they may also already beretracted before they reach this station, as this is shown in FIG. 1.

However, it is also possible to obtain the same movements of the pistons9 in the receiving openings 4 by cam discs 11 disposed outside the drum,and also a plurality of cam discs or curved paths disposed on pivotablelevers or the like, respectively, may be disposed, always one of thembeing related to one of the stations.

At the kneading station 6 disposed in the region of the upper summit ofthe drum 2 a kneading tool 16 is disposed which is formed in a knownmanner as a plate provided with stepped recesses 17. Always one of theserecesses 17 is disposed over a receiving opening 4 during the kneadingprocess of the dough piece disposed within the receiving opening 4. Thekneading tool 16 is driven to a circular movement by a motor 19 via anexcenter drive 18, whereby the surface of the dough piece disposedwithin the receiving opening 4 is taken along by the edge of the recess17 and by and by is changed into a spherical shape due to the circularmovement.

At the ejecting station 7 a conveyor belt 20 is disposed which is drivenin direction of the arrow 21 and is guided over a guide roller 22disposed adjacent the drum 2, however spaced a short distance from theperiphery thereof. The gap between this guide roller 22 and the outersurface 15 of the drum 2 is bridged by a transition roller 24 driven forrotation in direction of the arrow 23, which transition roller guidesthe dough pieces ejected from the pistons 9 smoothly onto the conveyorbelt 20.

At the portioning station 5 the dough is pressed into the receivingopenings 4 by a pusher member 25, the front surface 26 thereof is curvedcorresponding to the peripheral surface 15 of the drum. The pushermember 25 is driven in direction of the double arrow 29 by a swivellablelever 28 swivelled by a shaft 27. Its outermost front position is shownby full lines, its rear dead position by dotted lines. The pusher member25 is guided within a chamber 30 into which the dough to be portioned isfed in pre-portioned manner from a filler hopper 31 in which apre-portioning tool 51 is disposed which is constituted by two starrollers 32 having three arms, which rollers are supported for rotationaround horizontal axes disposed parallel to each other. Each one of thetwo star rollers for itself can be driven in one direction (arrows 33)only, so that the two star rollers 32 rotate in inverse sense, however,synchronously and intermittently. In the stillstand phase of theintermittent rotational movement shown in FIG. 1 the two star rollers 32shut off the path of dough through the filler hopper 31 by means oftheir arms facing each other. However, if the star rollers 32 are drivenfor rotation, they convey a piece of dough into the section of thefiller hopper 31 disposed below the star rollers 32 and therefore intothe chamber 30. In order to avoid that there is too much dough 34 in thechamber 30 so that the dough could be squeezed in an undiserable mannerwhen moving the pusher member 25, three capacitive sensors 35 responsiveto the approach of wet mass are embedded in that wall 36 of the chamber30 or the lower section of the filler hopper 31, respectively, which isdisposed parallel to the axis 3 of the drum 2 and neighbouring the drum2. Each one of these sensor 35 has the shape of a ledge extending oversubstantially the entire length of that wall 36 and being flush with theinner surface 50 of the wall 36. From these sensor 35 always only one iseffective. Each sensor 35 is so put into the drive of the star rollers32 that the sensor 35 allows this drive only then to move if the volumeof the dough 34 in the chamber 30 decreases a predetermined value. Assoon as this is the case, the star rollers 32 convey dough into thechamber 30. This conveyed amount of dough may be a predetermined amountof dough corresponding to a certain angle of rotation of the starrollers 32, or the arrangement may be such that the sensor 35 shuts offthe drive means of the star rollers 32 when the volume of dough in thechamber 30 has again reached a certain value.

The disposal of three sensors 35 one above the other enables one toadjust the dough volume in the chamber 30 to the volume of the doughportions to be produced. If smaller dough portions are to be produced,the lowermost of the sensors 35 is switched in and for bigger doughportions to be produced the middle one of the sensors and for big doughportions the uppermost sensor 35 corresponding to the greatest volume ofdough in the chamber 30. For this, the sensors can be at choice switchedin by means of a change-over switch 37 (FIG. 2), so that always one ofthe sensors 35 is connected via a line 52 to a control circuit 38 forthe drive means of the star rollers 32. The change-over switch 37 may bemechanically or electrically coupled to an adjustment member 39, forexample via a line 40, by which member the volume of dough of the doughportion to be produced can be adjusted. This adjustment member 39 maycomprise for example a gear means, in particular a worm gear, by meansof which the relative position of a swivellable arm 41 can be variedrelative to the shaft 13 carrying the cam discs 11. To the swivellablearm 41 a crank means is connected by means of which the oscillatingmovement of the shaft 13 or the cam discs 11 keyed to it is obtained. Bymeans of this adjustment member 39, therefore, also the relativeposition of the cam discs 11 relative to the drum 12 can be varied whichmeans an advancement or, respectively, retractment of the pistons 9 inthe receiving openings 4. Thereby, suitable shape of the curved paths 10provided, a bigger or smaller volume received by the receiving opening 4at the portioning station 5 can be adjusted and thereby the volume ofthe portioned dough pieces can be varied.

Further, it is suitable if also an adjustment member 42 for varying thekneading circumstances for the kneading tool 16 at the kneading station6 is coupled to the change-over switch 37 for switching the sensors andthe adjustment member 39 for the volume of the dough portions to beproduced. For example, the kneading space (volume of the receivingopening 4 at the kneading station 6) can be varied. For this, thepistons 9 at the kneading station 6 can be adjusted by means of theadjustment member 39 in an analogous manner to that which has beendescribed for the portioning station 5. Thereby it can be consideredthat a bigger dough portion requires a bigger end volume of thereceiving opening 4 in which this portion is disposed during thekneading process. As it has been described in connection with thevariation of the volume of the receiving opening 4 at the portioningstation 5, an automatic change-over to that sensor 35 can be obtained bya suitable electronic means at this change, which sensor corresponds tothe dough volume present.

In addition thereto, for each sensor 35 a separate means may be providedfor interrupting the backward movement of the pistons 9 during thekneading process for a certain time, what also corresponds to avariation of the kneading space of the kneading device in order to adaptone to the dough volume given by the selection of the sensor. For this,for each sensor 35 a cam disc 43 is keyed to the shaft 13 at the onefront side of the drum 2, therefore in total three cam discs, each ofwhich cooperates with an switch off-means 44 put into the power circuitof a magnetic coupling which couples the swivellable arm 41 or the camdiscs 49, respectively, to the shaft 13 carrying the cam discs 11. Assoon as the cam of the corresponding cam disc 43 hits a contact arm 49of the related switch off-means 44, the shaft 13 and together with itthe cam discs 11 remain at stillstand for a certain time, as long as thecam of the cam disc 43 leaves the contact arm of the switch off-means44. Thereby it is achieved that during the kneading process not only thedrum 2 stands still but for the same time interval also the cam discs 11so that during this time interval the pistons 9 stand still in thereceiving openings 4. Thereby it is ensured that at the beginning of thekneading process the piston 9 is retracted in the receiving opening 4(as long as there is a relative movement between drum 2 and cam disc11), and then remains in this partially retracted position for the sametime interval and is moved back for the remaining portion of theretracting distance after the drive means of the shaft 13 have beenswitched in again. Thereby, an optimal tension is given to the doughpiece during the kneading process and finally, after the dough piece hasbeen shaped to a ball-like or, respectively, spherical shape, the volumeof the receiving opening 4 is still somewhat increased so that the doughpiece already being closed loosens well from the kneading tool 16 or itsrecesses, respectively. By varying the time interval during which therotation drive of the shaft 13 is interrupted, this stillstand phase canbe easily adapted to the given king of dough piece, in particular to thevolume of the dough portion, For this, the cams of the cam discs 43 cannot only be directed to different directions (as this is excessivelyshown in FIG. 1), but they can be also shaped to different profiles. Ifdesired, also further cam discs can be provided for replacement foradaption to special circumstances.

The said interruption of the retracting movement of the cam discs 11 andthereby of the pistons 9 in the receiving openings 4 can also beobtained by switching off the main drive for the drum shaft 13 or,respectively, for the cam discs 11 for a predetermined time intervalwhich suitably is adjustable and selectable, however, the drive meansfor the kneading tool 16 being still in motion. For this, an arrangementcan be choosen as it is described for example in the Austrian patentspecification no. 352,653, for example a shaft driven from the mainmotor, a cam disc being fixed to this shaft and being provided with acam cooperating with a switch for switching off or, respectively, in thedrive means of the drum shaft 13, suitably via a magnetic coupling. Itis also possible that the switch operates a time switch which keeps thedrive means for the drum shaft switched off for a predetermined timeinterval which suitably is adjustable. This switch and, respectively, orthe switching cam can be adjustably disposed in order to provide forfurther adjustment possibilities.

I claim:
 1. Apparatus for portioning dough comprising:frame means; afiller hopper on said frame means for holding dough therein, said fillerhopper including an open bottom and a side wall having an interiorsurface and an exterior surface; pre-portioning means in said fillerhopper for preportioning said dough; a dough chamber on said framemeans, said dough chamber having an open top for receiving dough fromthe open bottom of said filler hopper, and an open front end; acylindrical drum having an outer surface and at least one cavitytherein, said cavity opening outwardly through an aperture in said outersurface, said drum being rotatably mounted on said frame mans forrotation about a horizontal axis wherein the outer surface thereofrotates in closely spaced, adjacent relation to said front end of saiddough chamber, a pusher member in said dough chamber for pushing saiddough outwardly of said dough chamber into said cavity in said drum whensaid cavity is positioned at the front end of said dough chamber;stripper means on the exterior surface of said side wall adjacent thefront end of said dough chamber, said stripper means cooperating withthe outer surface of said drum to strip away excess dough from theaperture of said cavity when said cavity is rotated away from the frontend of said dough chamber; means for adjusting the volume of saidcavity; at least two capacitive sensors mounted in vertically spacedrelation on the interior surface of said side wall, said sensors beingresponsive to the approach of a moist mass of dough; switch meansassociated with said capacitive sensors and said adjusting means forselective operation of one of said sensors in dependence on the volumeselected for the cavity; and drive means for intermittently driving saidpreportioning means in dependence upon the amount of dough sensed by theoperative capacitive sensor.
 2. In the apparatus of claim 1, saidcapacitive sensors being imbedded within said side wall.
 3. In theapparatus of claim 1, said capacitive sensors having a generally flatsensing surface, said sensors being mounted in said side wall so thatsaid sensing surface is flush with said interior surface of said sidewall.
 4. In the apparatus of claim 1, said side wall having a front wallportion adjacent the front end of said dough chamber, said capacitivesensors comprising elongated sensors which are mounted in said frontwall portion, said elongated sensors extending horizontally alongsubstantially the entire length of said front wall portion parallel tothe axis of the drum.
 5. In the apparatus of claim 1, said drum havingan upper summit region, said apparatus further comprising kneading meansdisposed at said upper summit region.
 6. In the apparatus of claim 5,said cavity defining a kneading space, said apparatus further comprisingmeans for increasing the volume of said kneading space as said cavity isrotated to a position adjacent said kneading means, said means forincreasing said volume being associated with said switch means and saidadjustment means for automatically selecting an increased volume of saidkneading space in dependence on the volume selected for said cavity. 7.In the apparatus of claim 1, said pre-portioning means comprising a pairof star rollers rotatably mounted in said filler hopper for synchronousrotation in opposite directions.
 8. In the apparatus of claim 1, saidcapacitive sensors being mounted in said side wall adjacent to the frontend of said dough chamber.